1. Field of the Invention
The embodiments, described herein relate to user interfaces. More particularly, the systems and methods herein relate to touch interfaces that are able to register multiple, simultaneous touches. Some embodiments described herein relate to pressure-sensitive touch interfaces.
2. Description of the Related Art
Existing row/column touchpad approaches have limitations on registering multiple touches. A third touch position which falls on the same rows and columns as two existing touches will not be registered.
Furthermore, most consumer touch interface devices use capacitive sensing, which are typically not pressure-sensitive because of the sensitivity limitations inherent in capacitive solutions. A pressure-sensitive touch interface would increase the functionality of a touch interface through the use of touches of varying pressure (i.e. using a “hard” touch as opposed to a “soft touch” to bring up a background menu control).
Although current resistive technology can be pressure-sensitive, resistive solutions are not common in practice because of light-touch sensitivity limitations.
Piezoresistive materials are typically not used in touch interface devices since they have a pressure-sensitive resistance that is typically responsive only to pressures higher than that of a light touch. As a result, simply adding a sensor to a piezoresistive material may result in a touch interface that is difficult to use in practice because the user must press very hard to obtain a response.